This invention relates to a diagnosing device for diagnosing an operating state of an object, by taking in predetermined information from an article identification device disposed in, on or near the object. The predetermined information is for identifying the object and may include, for example, the model of the object, the object number attached to the object for management purpose and so forth. The present invention relates also to such article identification device, and also an operation diagnosing system including a combination of such operation diagnosing device and such article identification device.
An example of known identification devices is a bar code. Information, such as the model and object number for use in management of an object of which operating state is to be diagnosed, is converted into a bar code and printed on a label. The label is attached directly to the object or indirectly on a plate, for example, which is disposed near the object. An optical reader is used to read the bar code when the operation of the object is to be diagnosed. Thus information about the object, such as the model and object number of the object to be inspected, can be read easily without resort to human eyes. The information thus read by means of the optical reader can be automatically inputted into an operation diagnosing device, whereby data inputting at the time of diagnosing and managing objects can be done at an increased efficiency.
When a bar code is used to identify an object, a reading head of an optical reader must be brought into contact with or placed directly in front of the object. Therefore, it is inevitable to dispose a space in front of the bar code label to allow the reader head to be placed therein. Thus, locations where bar code labels can be placed are disadvantageously restricted.
Another problem with the use of bar codes is that stains and scratches on surfaces of bar code labels may cause erroneous reading or make it impossible to read the bar codes. This problem may be worsen when bar codes are attached to objects used in environments where the bar codes are subjected to dust and staining materials, e.g. in plants or the outdoors.
The above-described apparatus requires, in addition to a diagnosing device, a separate optical reader when diagnosing operations of objects, which makes the operation diagnosis cumbersome.
Therefore, an object of the present invention is to provide an article identification device which can be placed almost anywhere and of which the function is hardly affected by stains and scratches.
Another object of the present invention is to provide an object operation diagnosing device which includes a function for taking in information borne by the article identification device and which is easy to handle. A further object of the present invention is to provide an object operation diagnosing system composed of a combination of the article identification device and the operation diagnosing device.
An operation diagnosing device according to the present invention includes a first transmitter section outputting a first transmission signal, a first transmitting element receiving the first transmission signal from the first transmitter section, converting the received first transmission signal into a first RF signal and radiating the first RF signal into a space, a first receiving element receiving a second RF signal from the space and converting the received second RF signal into a first reception signal, and a first receiver section receiving the first reception signal and deriving predetermined information of an object to be diagnosed from the first reception signal.
An article identification device according to the present invention includes a second receiving element receiving the first RF signal from the space and converting it into a second reception signal, and a second receiver section receiving the second reception signal from the second receiving element and generating and outputting a command to respond. The article identification device further includes a second transmitter section which includes a memory, e.g. a semiconductor memory, in which predetermined information relating to the object to be diagnosed has been stored. The second transmitter section outputs a second transmission signal containing the predetermined information stored in the memory when the command to respond from the second receiver section is applied to it. The article identification device also includes a second transmitting element which receives the second transmission signal, converts it into the second RF signal and radiates the second RF signal into the space. The article identification device is mounted in, on or near the object to be diagnosed directly or indirectly by means of a suitable mounting means.
An object operation diagnosing system according to the present invention includes the above-described diagnosing device and one or more article identification devices described above. With the diagnosing system, the first RF signal is transmitted to and received by the article identification device and the second RF signal is wirelessly transmitted to and received by the diagnosing device.
The predetermined information relating to an object is information by which the object can be identified and may include, for example, information about the model of the particular object, an object number arbitrarily assigned to the object, the specification of the object and/or the location where that object is disposed.
The diagnosing device radiates the first wireless RF signal into the space around it. When the diagnosing device is brought near to the article identification device, the first RF signal is received by the article identification device with an increased field strength. When the RF signal is received with a field strength above a predetermined level, the article identification device radiates the second RF signal containing the predetermined object information stored in the memory in response to the first RF signal. The diagnosing device receives the radiated second RF signals from the article identification device, and retrieves the predetermined information in the second RF signal, whereby the object to be diagnosed can be correctly identified.
Thus, according to the present invention, the object identifying information is transmitted wirelessly, i.e. in a noncontact fashion, from the article identification device to the object operation diagnosing device.
The first transmitter section of the diagnosing device may be arranged to output the first transmission signal only when a command to transmit the first transmission signal is externally applied to it.
The operation diagnosing device according to the present invention has not only a function to measure some quantity or quantities indicating the operating state of an object and determine whether or not the object is operating normally, but also a function to take in information regarding the object from the article identification device associated with the object. The means for realizing the taking in of information, namely, the first transmitter section, the first transmitting element, the first receiving element and the first receiver section are placed together with diagnostic means in a common casing.
The first transmitting element and the first receiving element may be realized by a single device, so that the diagnosing device can be simplified and manufactured at a lower cost.
The operation diagnosing device may be provided with a setting unit for automatically setting or selecting part or all of the information retrieved by the first receiver section in the diagnosing device. For example, by so arranging the diagnosing device as to be able to automatically set data contained in the retrieved information relating to an object, such as the type or model of the object and the management number, troublesome inputting of such data can be avoided.
The first transmission signal is, for example, an alternating signal with fixed frequency and amplitude, such as a single-frequency sine-wave signal and a square pulse signal with fixed pulse width and period. Since the first RF signal need be received and recognized by the article identification device simply as a request from the diagnosing device for sending back the information regarding the object to the diagnosing device, and it need not contain any other special information. Therefore, the first transmission signal from which the first RF signal is prepared need be simply an AC signal. In other words, the first transmission signal can be a simple carrier, so the first transmitter section can have a simple structure, which makes it possible to manufacture the device at a lower cost.
The second transmitting element and the second receiving element of the article identification device may be formed as a single device, whereby the device can have a simplified structure and be manufactured at a lower cost.
The second receiver section may be so arranged as to derive power from the received first RF signal sent from the diagnosing device and to output the derived power as the command to respond. Then, the second receiver section can be formed of a rectifying circuit or rectifying and smoothing circuit including only passive devices. Since the power for driving the second receiver section including the memory is derived from the first RF signal sent from the diagnosing- device, no separate power supply need be provided for the article identification device. This can simplify the structure of the identification device and makes it possible to manufacture it at a lower cost.
Part or all of the respective constituents of the article identification device, namely, the second receiving element, the second receiver section, the second transmitter section and the second transmitting element, may be formed in a single unit by, for example disposing them in a single casing. This makes the article identification device compact, and the management and handling of the identification devices are easy.
The first RF signal may be inductively transmitted from the first transmitting element to the second receiving element of the article identification device, so that they can be inductively coupled. Inductive coupling of the first transmitting element with the second receiving element can suppress propagation loss of the first RF signal, which, in turn, makes it possible to reduce the power to be used in transmitting and receiving the RF signal.
Similarly, the second RF signal may be transmitted from the second transmitting element in the article identification device to the first receiving element on the operation diagnosing device, by placing the operation diagnosing device close to the article identification device, which can also reduce the power to be used in transmitting and receiving the RF signal.
The present invention can be used for diagnosing the operation of known trap devices, e.g. steam traps and gas traps, disposed in piping. It is known that, for precise diagnosis of the operation of trap devices, data such as parameters for use in diagnosing corresponding to models and specifications of respective trap devices must be inputted into a diagnosing device. According to the present invention, such data can be wirelessly taken from the identification device. In order to make precise diagnosis, parameters necessary for diagnosing a particular object should be set in the operation diagnosing device. According to the present invention, such parameters can be automatically selected based on the information received from the article identification device, which eliminates manual selection and inputting of such parameters.